Historically, telecommunications involved the transmission of voice and fax signals over a network dedicated to telecommunications, such as the public switched telephone network (PSTN) or a private branch exchange (PBX). Data networks, which may include a local area network (LAN), wide area network (WAN), or a global distributed network such as the Internet, may also provide telecommunications services, such as packet-based telecommunications. One type of packet-based telecommunications architecture includes a number of end-user devices managed by a controller that establishes, maintains, and terminates communication sessions among the different devices.
To participate in a communication session, end user devices typically register with a controller. When the controller becomes unavailable due to equipment malfunction or network congestion, registered devices may seek a backup or secondary controller to receive communication services. When the primary controller becomes available, many of the devices may try to re-establish registration at nearly the same time, placing an extreme registration load on the primary controller.